This invention relates to a straw spreader for spreading straw discharged from a combine harvester.
For zero till and low till farming practices, it is fundamentally more important to ensure that straw discharged from the rear discharge opening of a combine is spread effectively over the ground. This spreading action prevents the collection of trash at specific locations on the ground which would interfere with seeding in the subsequent harvesting year. In addition the effective spreading of the straw across the ground can assist in retaining moisture over most of the ground rather than in specific areas where the straw lands if not properly spread. Furthermore the nutrients from the straw are applied equally across the ground.
Conventionally the combine harvester includes a chopper at a rear discharge opening of the combine so the straw emerging from the rear of the straw walkers is vigorously chopped into short lengths and discharged rearwardly and downwardly from the rear opening of the combine. This action merely dumps the straw onto the ground in a stream behind the combine with little or no spreading action to the sides. Other devices have been proposed for addition onto the combine to provide a chopping and spreading action. One problem which arises with devices of this type is that they are mounted relatively high on the combine and this causes the spreading action to be adversely affected by wind movement. This wind effect on the straw can alter the desired even spread so the material is spread in bands across the ground. Furthermore, the relatively high discharge causes the wide spread of large amounts of dust which can interfere with the driver's operation of the combine.